GB2067891A

GB2067891A - Dishwashing machine

Info

Publication number: GB2067891A
Application number: GB8101024A
Authority: GB
Original assignee: Licentia Patent Verwaltungs GmbH
Current assignee: Licentia Patent Verwaltungs GmbH
Priority date: 1980-01-25
Filing date: 1981-01-14
Publication date: 1981-08-05
Also published as: IT8120544V0; DE3002625A1; FR2474301A3; DE3002625C2; FR2474301B3

Abstract

A dishwashing machine is provided with level regulating means comprising a duct (1) which is connected to the rinsing chamber of the machine, said duct having a wall (2) with overflow edge (3) at the height of normal level (4) in said chamber, an overflow channel (5), a chamber (6) divided by wall (7) to form air traps (8), (9), connected by conduits (10), (13) to level switches (not shown), and a siphon duct (15). In use, when the water level in the rinsing chamber rises above normal level (4), water flows into duct (1) over edge (3) into chamber (6), causing air trapped in trap (8) to actuate a level switch to close a water inlet valve and start up a circulating pump, thereby lowering the water level. If, because of some defect the water level rises with the circulating pump operating, the other level switch is actuated when level (11) is reached to operate an emptying pump, which also removes water from duct (1) via siphon duct (15). <IMAGE>

Description

SPECIFICATION Dishwashing machine The present invention relates to a dishwashing machine.

In a known dishwashing machine (DE-OS 26 24 219), the connections of an air trap chamber for the hoses of level control switches are disposed at the level of a lid of the chamber so that the openings of associated connecting stub pipes are disposed below the liquid level of a rinsing chamber of the machine.

There is a need for a dishwashing machine with a form of level regulation in which water cannot run out of the machine if the level switch hoses becoming leaky or detach from the connecting stub pipes.

According to the present invention there is provided a front-loading dishwashing machine comprising means defining a rinsing chamber fillable through a side duct with liquid to a predetermined normal level, and filling level regulating means comprising a control chamber, which is separated from the side duct of the rinsing chamber by means defining an overflow channel having an overflow edge at said normal level and which is divided by intermediate wall means into two separate air traps communicating with each other at the base of the control chamber and with the overflow channel, two duct means each communicating with a respective one of the air traps and each provided with outlet connection means for connection thereto of a conduit to a respective pressure-operated level control switch means, one of the outlet connection means being disposed above said normal level and the other outlet connection means above a safety filling level above the normal level, and a siphon duct connected to the base of the control chamber to communicate with the air traps and connected to pump means for emptying the chambers.

In a machine embodying the present invention, water cannot run out of the machine if the switching means conduits become leaky or detach from the outlet connection means. Moreover, the switching means associated with said outlet connection means above the normal filling level responds in the event of a leaky conduit of the other switching means, for example when the water inlet valve does not close according to the machine programme, the first-mentioned switching means being able to switch on the pump means to drain out the water and thereby stop water from issuing through the outlet connection means for the conduit of said other switching means.Similarly, water does not leak out in the event of a leaky connection between the conduit of the first-mentioned switching means and the respective outlet connection means, as the water level of the rinsing chamber monitored by said other switching means lies below the outlet opening of that outlet connection means.

An embodiment of the present invention will now be more particularly described by way of example and with reference to the accompanying drawing, which is a schematic sectional elevation of level regulating means in a dishwashing machine according to the said embodiment.

Referring now to the drawing, there is shown level regulating means for a front-loading dishwashing machine, the level regulating means comprising a side duct 1 or the like, which is connected with the ringing chamber (not shown) of the machine and in which is arranged a separating wall 2 with an overflow edge 3 at the height of a normal level 4 (with a circulating pump switched off) of the rinsing chamber. An overflow channel 5 arranged behind the separating wall 2 opens into a control chamber 6 of small volume compared with that of the rinsing chamber.

The chamber 6 is subdivided by an intermediate wall 7, which ends at a spacing above the chamber base, into two air traps 8 and 9 for a normal level switch and a safety level switch (not shown), respectively. A connecting pipe 10 moulded onto the body of the chamber 6 extends from the air trap 8 above a safety level 1 1 (the level of the filling of the rinsing chamber at which the safety level switch responds and switches on an emptying pump) so that the outlet of a connecting stub pipe 12 thereof is disposed at a spacing b above the level 11, a hose leading to the normal level switch being connectible to the stub pipe 2.A further connecting pipe 13 moulded onto the body of chamber 6 extends from the second air trap 9 above the normal level 4, so that the outlet of a connecting stub pipe 14 thereof for a hose of the safety level switch hose is disposed on the one hand below the stub pipe 12 for the normal level switch hose and on the other hand at a spacing a above the normal level 4.

When the dishwashing machine is switched on after closing of a loading door thereof, water initially runs into the rinsing chamber with the circulating pump stationary. When the water level of the rinsing chamber reaches the normal level 4, water runs into the side duct 1 and over the overflow edge 3 of the wall 2 into the chamber 6.

Due to the small volume of the chamber 6, the air trap 8 is quickly filled with water to a level corresponding with the switching value of the pressure switch for the normal level 4. The normal level switch closes the water inlet valve and the circulating pump can start up, whereby the water level in the rinsing chamber is lowered below the normal level. The water level in the overflow channel 5 or in the chamber 6 remains in the range between the switching values of the normal level switch in case the inlet valve and this pressure switch function properly.

If a fault arises and further water runs into the rinsing chamber, for example because of a leaking valve, the water level in the rinsing chamber rises and reaches the overflow edge 3 again even with the circulating pump in operation. Water overflowing into the overflow channel 5 as a result reaches a level corresponding to the switching value of the safety level switch, which then switches on the emptying pump. By means of this pump, the level of water in the rinsing chamber and in the side duct 1 is lowered. With the emptying pump in operation, the water level in the overflow channel 5 is lowered via a siphon duct 1 5, which extends from the base of the chamber 6 to the emptying system of the emptying pump, until the safety level switch is again switched back and switches off the emptying pump. If the fault is not eliminated, the level in the rinsing chamber again rises until the safety level switch switches the emptying pump back on.

The outlet openings of the connecting stub pipes 13 and 10 are disposed at such heights above the normal and safety filling levels of the rinsing chamber that no water outflow can occur at these points. By virtue of the higher arrangement of the outlet opening for the normal level switch, it is ensured that the safety level switch remains capable of responding in the event of a leaky normal level switch hose connection without water being able to issue from the stub pipe 12 for the normal level switch.

Claims

1. A front-loading dishwashing machine comprising means defining a rinsing chamber fillable through a side duct with liquid to a predetermined normal level, and filling level regulating means comprising a control chamber, which is separated from the side duct of the rinsing chamber by means defining an overflow channel having an overflow edge at said normal level and which is divided by intermediate wall means into two separate air traps communicating with each other at the base of the control chamber and with the overflow channel, two duct means each communicating with a respective one of the air traps and each provided with outlet connection means for connection thereto of a conduit to a respective pressure-operated level control switch means, one of the outlet connection means being disposed above said normal level and the other outlet connection means above a safety filling level above the normal level, and a siphon duct connected to the base of the control chamber to communicate with the air traps and connected to pump means for emptying the chambers.

2. A machine as claimed in claim 1, said means defining the rinsing chamber comprising a wall projecting above said normal level in the region of a loading door of the machine.

3. A machine as claimed in either claim 1 or claim 2, said intermediate wall means comprising a wall member extending in the control chamber to end at a spacing above the base thereof.

4. A machine as claimed in any one of the preceding claims, said duct means each comprising a respective pipe formed integrally with means defining the control chamber.

5. A front-loading dishwashing machine substantially as hereinbefore described with reference to the accompanying drawing.